A cigarette lighter in a child's possession is potentially quite dangerous, and therefore it is not surprising to see several prior art devices that address such a hazard. For example, U.S. Pat. No. 4,717,335 to Loveless on Jan. 5, 1988, illustrates a child resistant lighter that limits the rotation of a spark producing wheel unless a small lever is actuated first. However, such a device still permits a fuel valve to be actuated, which may still result in fuel ignition from another source. U.S. Pat. No. 5,076,783 to Fremund on Dec. 31, 1991, teaches a safety lighter that restricts the movement of a fuel valve actuator lever unless a safety latch at the bottom of the lighter is previously actuated. However, such a device still allows the spark producing wheel to produce sparks, which may result in ignition of some flammable substance other than the lighter's fuel.
Typically, prior art safety lighters either restrict the rotation of the spark producing wheel or restrict the actuation of the fuel valve, but not both. As a result, undesirable ignition of flammable substances may still occur with such devices. Moreover, many children will quickly discover how to overcome, the single safety features of the prior art devices. However, if there were more than one such safety features incorporated into a single safety lighter, many children would become bored with trying to operate the lighter and cease trying.
Another prior art safety lighter device, disclosed in U.S. Pat. No. 4,799,877, limits the use of the lighter unless the lighter is partially pulled from a restrictive housings. However, if a person using such a device forget to return the lighter to its fully inserted position into the housing, the valve restricting means will not operate. As a result, a child may freely use such a lighter.
Clearly, then, there is a need for a safety lighter that both limits the rotation of the spark producing wheel and limits the fuel valve actuation lever. Such a needed device would automatically reset itself after use, such that the user would not need to remember to manually lock or restrict the lighter mechanisms. The present invention fulfills these needs and provides further related advantages.
Another design for a lighter having safety interlocking means is described in a co-filed U.S. patent application. This other design provides certain safety advantages including a first safety assembly for controlling the fuel delivery valve including a pair of adjacent, concentrically aligned rings providing engagement notches therein for accepting engagement by an elongated portion of the fuel delivery valve actuator. The engagement of the elongated portion with the aligned engagement notches allows the valve actuator to be depressed, whereby fuel flows from the fuel supply tank through the fuel delivery valve. At least one of the rings is rotatable such that the two engagement notches, when manually released, become nonaligned, thereby preventing fuel from flowing from the fuel supply tank through the fuel delivery valve. A second safety assembly controls the production of the spark and provides a toothed wheel for rotating with the spark producing wheel. A tongue is held by the case in a position for engaging the toothed wheel such that the wheel is prevented from rotating so that the spark producing capability of the spark producing wheel is disabled. A spring is further included for providing engagement force for normally holding the toothed wheel against the tongue. The toothed wheel is mounted onto an axle supported in a pair of elongated holes, such that the toothed wheel may move into and out of engagement with the tongue. One drawback of my other design is that the friction wheel may be turned by a child after some experimentation, and indeed the same is true of the interlock on the fuel valve mechanism.
The present invention both limits the rotation of the spark producing wheel and limits the fuel delivery means in a manner that may be constructed to require an adult sized hand since two levers must be actuated together and in sequence. Further, the present invention automatically resets itself after use, such that the user does not need to remember to manually lock or restrict the lighter mechanisms after each use. Other features and advantages of the present invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention.